1. Field of the Invention
This invention relates to smart-stores, and more particularly to a smart-store emulation unit for use on-board a weapon platform in place of the physical presence of a smart-store to conduct operator training on or testing of the smart-store.
2. Description of the Related Art
Aircraft carry and release stores (e.g. bombs, missiles etc.) to engage targets. On older aircraft, with “dumb” stores the pilot simply pressed the “pickle” button on the hands-on throttle and stick (HOTAS) to send a signal via a hardwired cable to the rack or pylon to release the store. On more recent aircraft that carry precision-guided “smart-stores” (e.g. GPS, laser or RF guided) an additional electrical interface provides for bidirectional communication of data between the aircraft and store via a message set over a separate hardwired cable. Other smart-stores include launchers, targeting pods, etc. An Interface Control Document (ICD) defines both the functional behavior of the smart-store and the message traffic to and from the store to effect data transfer via the electrical interface in sufficient detail that the store can be connected to a weapon platform (such as an aircraft) and either control or be controlled by the platform.
U.S. and several foreign designed aircraft built, after the early 1970s such as the A-4, AV-8, F-4, F-15, F-16, F/A-18, F-111 and so on include an AGM-65 (“Maverick”) analog interface. The aircraft interface provides discrete signals such as uncage, station select, AGM-65 select, launch, track, and others . . . on discrete input signal lines that change state depending on how the aircrew manipulates the Maverick controls. For example, pressing the Maverick “Track” button, typically located on the HOTAS, momentarily causes the “track” signal to go high. The aircraft interface further provides two variable analog slew signals on analog input signal lines that are used to slew the gimbaled seeker on the store in azimuth and elevation. The store interface receives analog video from the seeker (e.g. infrared sensed imagery or output from a TV/CCD sensor) and transmits the video over a video output signal line where the video can be viewed by the aircrew in the cockpit. The store interface also provides discrete signals an discrete output signal lines such as launcher present, AGM-65 identification MSL ready, etc. to the aircraft.
In the early 1990s, the U.S. Department of Defense promulgated MIL-STD-1760 that defines a digital interface, hardware and software for aircraft and stores. Newly produced tactical aircraft are internally wired with a 1760-compatible data bus for coupling to the MIL-STD-1760 standard store interface. Modern smart weapons such as the Joint Direct Attack Munition (JDAM), Joint Standoff Weapon (JSOW) or ENHANCED PAVEWAY™ bomb are designed to communicate with the aircraft via such an interface to obtain control, monitor and firing information to carry out mission critical operations. The ICD defines the functional behavior and 1760-compliant message traffic of the store.
These modern smart stores such as bombs, missiles and smart projectiles compute and update their Launch Acceptability Region (LAR) to engage a target on the ground or in the air. The LAR defines a region of conditions where a store can be successfully launched to reach a specified target. In the case of a weapon released from an aircraft, these launch conditions usually take into account real time variables like the range to the target, the speed, altitude and attitude of the aircraft, and the capabilities of the weapon itself under those conditions. The primary factors that typically limit the launch envelope of a store are its kinematic performance and seeker capabilities. The store executes store-specific LAR algorithms (as implemented in store-specific software) to update the LAR. The 1760 interface allows the store to generate and transmit a LAR data message to the aircraft, which in turns generates the LAR display to be viewed by the aircrew in the cockpit.
The overwhelming majority of legacy aircraft in use today lack either the proper hardware and/or software to communicate with modern stores using the store's MIL-STD-1760 interface. Economic and political constraints dictate that the lives of existing aircraft must be extended, making the incorporation of new 1760 stores into existing aircraft highly desirable if not necessary. Integration of new 1760 stores with legacy “Maverick” aircraft or aircraft with no existing interface requires significant hardware and software modifications to the aircraft. Such modifications are both complex and costly to design and implement and may not provide the full functionality of the 1760 store. RAYTHEON COMPANY has developed Munitions Control Units (MCUs) that allow AGM-65 aircraft to control modern 1760 stores (see U.S. patent publication 2010/0217899 and U.S. Pat. No. 7,802,048) without modification to the aircraft's hardware and software.
Pilots of either modern 1760-compatible aircraft or legacy “Maverick” aircraft must be fully trained on the use of these 1760 smart-stores. Pilot training may be a combination of a full-up simulator that simulates both the aircraft and smart-store, a real aircraft with live smart-stores, and a real aircraft with simulated smart-stores. The latter involves simultation software that is built into the aircraft and is often known as “zero quanitity” training in reference to the lack of a physical smart-store.